Defined Benefit Plans (Components of Net Periodic Benefit Cost of Other Postretirement Benefit Pension Pans) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ (11.2)	$ (10.0)	$ (22.1)	$ (19.8)
Net periodic pension benefit (cost)	(2.9)	(3.0)	(6.0)	(5.9)
Other postretirement benefit plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	(0.2)	(0.2)	(0.3)	(0.4)
Interest cost	(1.1)	(1.3)	(2.3)	(2.6)
Amortization of prior service credit	(0.6)	(0.8)	(1.2)	(1.6)
Net periodic pension benefit (cost)	$ (0.7)	$ (0.7)	$ (1.4)	$ (1.4)